The Windows 7 taskbar is designed such that it can used as a dockbar. So if you are using like one you are probably missing one item that every dockbar software generally has – the separator.
A separator is a line that separates one icon from the next and helps to group icons together.
Taskbar Separators comes in 4 colors; Black, White, Blue, and Red. The author provides a base icon file that you can edit in any good image editor to create custom colored separators. The separators are simple EXE files that you just drag and drop to the taskbar.